ATLANTA - A state judge Friday dismissed two key portions of a lawsuit challenging the planned construction of Georgia's first new coal-burning power plant in 25 years.

But Administrative Law Judge Stephanie Howells reserved ruling on a third allegation and declared that the two environmental groups bringing the suit are legally qualified to do so, a decision that would have stopped the case in its tracks had it gone the other way.

The Sierra Club and Friends of the Chattahoochee are appealing a state permit issued in May for the 1,200-megawatt Longleaf Energy Station in Southwest Georgia's Early County. It would become Georgia's 11th coal-fired power plant.

The $2 billion project has drawn strong support from many local residents because of the job-creating promise it holds for the rural county.

But environmental activists say the plant would add to an already high level of pollutants being spewed into the air.

The suit charges that the state Environmental Protection Division failed to place any limit in the permit on the plant's emissions of carbon dioxide, which has been linked to global warming.

During Friday's arguments, a lawyer for the environmental groups cited a U.S. Supreme Court ruling last spring in a case brought by Massachusetts that the federal government must begin regulating carbon dioxide to comply with the Clear Air Act.

But Patricia Barmeyer, a lawyer representing Longleaf, said the Supreme Court only ruled that the U.S. Environmental Protection Agency has the authority to regulate carbon dioxide, not that it must do so.

"At some point, carbon dioxide may become a regulated pollutant," she said. "But it's not one today."

Howells sided with Barmeyer's argument and also ruled in Longleaf's favor on an attempt by the environmental groups to require the company to limit the plant's emissions of particulate matter - tiny particles suspended in the air - to a stricter standard approved by the EPA a decade ago.

George Hays, the groups' lawyer, said the more lenient standard the state plans to use wouldn't protect people living in the path of the plant's emissions.

"It's become associated with some nasty problems, including premature death from cardiac arrest," he said.

But Barmeyer said officials at the EPA's regional office in Atlanta gave the EPD permission to use the more permissive standard because the federal agency still hasn't completed imposing the regulations governing the stricter requirement.

Hays also argued that Longleaf should be required to install what is known as IGCC technology at the plant, which converts coal into gas before burning it.

He cited a provision in the Clean Air Act that requires utilities and other industries to use the "best available control technology" to limit their smokestack emissions.

"IGCC is superior, producing the product they want, energy, with less environmental impact," Hays said.

But Les Oakes, also representing Longleaf, said the EPD made the right call in deciding that the pollution controls the company does plan to use - including low-sulfur coal and "innovative combustion techniques" fit the definition of the best available technology.

Hearings on the rest of the 17 counts in the lawsuit are set to resume early next month.